Delivery stripper finger



Oct. 25, 1932. B F, UPHAM 1,884,397

DELIVERY STRIPPER FINGER Filed Jan. 14, 1929 WITNESSES @km @53M @M1 *wwwfatented ct. 25, 1932 UNTED STATES PATENT OFFICE BURT FROST UPI-IAM, FBROOKLINE, MASSACHUSETTS, ASSIGNOR TO MILLER PRINTING .MACHINERYCOMIPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIADELIVERY STRIPPER FINGER Application filed January 14, 1929. Serial No.332,473.

My invention pertainsI to delivery stripper fingers for cylinderprinting presses, that is to say, to the fingers ordinarily employedupon cylinder printing presses for disengaging the printed sheet fromthe cylinder and directing it to the tapes or other deliverycontrivances.

Stripper fingers as heretofore constructed have presented continuoussurfaces of material length over which the printed sheet has i beenrequired to slide in being delivered from the printing cylinder. Thesheets, in their passage through the press or otherwise, frequentlyaccumulate charges of static eleci tricity which result in an attractionbetween l" the sheets and the stripper fingers and consequently asticking action which sometimes hinders the proper operation of thepress. This sticking action may cause a. retaining of the leading edgeof the sheet, whereby the l sheet, especially a sheetof thin paper ortissue, is caused to buckle between the stripper fingers and thecylinder instead of maintaining a straight line in being delivered. Orthe trailing edge of the printed sheet may adhere d to the stripperfingers, with the result that the sheet remains on the delivery tapes,with its trailing edge stuck to the stripper fingers, instead of beingdelivered in the proper manner. Sometimes the trailing edge of the sheetwill adhere to the stripper fingers at one side of the press but not atthe other side, wherefrom a slewing of the sheet o-n the delivery tapes,and consequently a failure of proper delivery, may result.

It is the principal object of my invention to obviate the difficultiesabove referred to by minimizing the opportunity for adhesion between theprinted sheet and the stripper fingers owing to static charges. I edectthis by reducing the area of the surfaces of the stripper fingers whichwill be engaged by the sheets during their delivery.

In the accompanying drawing:

Fig. 1 is a side elevation of a stripper finger constructed inaccordance with my invention, shown in association with a printingcylinder' diagrammatically illustrated; and Fig. 2 is a plan of thefinger.

In the drawing, indicates the surface of a printing cylinder and 11 theordinary tumbler grippers carried thereby. Placed adj acent the cylinderon the delivery side thereof in theJ usual manner is a stripper shaft 12carrying a series of stripper ngers 13, of which only one is shown. Theshaft 12 is rocked in a well known manner so that the points of thestripper fingers come into close proximity with the cylinder during thedelivery revolution ofthe latter but are spaced away from the cylinderduring the printing revolution.

According to my invention, the upper faces of the stripper fingers areserrated, instead of forming continuous surfaces as has heretofore beencustomary. Such serrations take the form of teeth 14 which are inclineddownwardly from the delivery towards the feeding side of the press. Theteeth are also tapered in a vertical plane towards the delivery side ofthe press, as may be seen from the plan, Fig. 2. Thus points 15 areformed, arranged in line with each other, and the printed sheet passesover and is supported by these points in being delivered from thearising from the printed sheets adhering to the stripper fingers.

I claim:

In a printing press, the combination with an impression cylinder of astripper finger for stripping the printed sheets therefrom and directingsaid sheets to a delivery device, whereby the printed sheets slide overand past said finger, said finger having the edge thereof formed with aplurality of serrations inclined downwardly towards the cylinder andtapered away from the cylinder on a vertical plane.

In testimony whereof, I sign my name.

BUR-T FROST UPHAM.

